import javax.swing.*;
class Notebookmain {
    public static void main(String[] args) {
        try {
            String lookAndFeel = UIManager.getSystemLookAndFeelClassName();
            UIManager.setLookAndFeel(lookAndFeel);//异常
        }catch (Exception e) {}
        MainFrame myFrame = new MainFrame();
        myFrame.setVisible(true);
    }
}